The present invention relates to medical diagnostic instruments, in particular to a vaginal speculum for visual examination of the vaginal cavity, vaginal walls, and conditions of the cervix.
A vaginal speculum is a diagnostic instrument for dilating the opening of the vagina cavity in order that the interior may be more easily visible for observation. A vaginal speculum has two expandable blades, which are inserted into the vagina in a closed state and then expanded, or moved apart for dilating the vaginal cavity. In particular, a vaginal speculum is an indispensable instrument not only for gynecologists but also for primary care physicians, geriatricians, urologists, and nurse practitioners for urological examination of patients suffering from urinary incontinence in order to exclude the presence of vaginal prolapses, such as rectocele, cystocele, enterocele, and uterine prolapse. Vaginal prolapses of the aforementioned type are protrusions or herniation of the urethra or other pelvic organs into the vagina.
One typical vaginal speculum is described in U.S. Pat. No. 3,716,047 issued in 1973 to W. C. Moore et al. The instrument consists of three parts of molded non-toxic plastic materials, i.e., a fixed member, a movable member, and a sliding member. The sliding member is slidingly installed in the fixed member and pivotally supports the movable member so that the movable member can be rotated around the pivot at the proximal end of the fixed member. As a result, the distal ends of the movable and fixed members, which form expandable blades insertable into the vagina, can dilate the vagina cavity and thus allow internal vaginal observations. The members are made from a transparent plastic and the blades form a thin-wall circular or oval cross-section, which allows the observation. In the context of the present invention, the term xe2x80x9cdistalxe2x80x9d is used with regard to the end of the speculum remote from the user""s hand, while the end on the side of the part 26 is referred to as a proximal end of the speculum.
A procedure of examination of a vagina with the use of a speculum involves movements of the speculum in an expanded, i.e., an outwardly diverging state in the direction towards or away from the uterus. This is necessary for diagnosing aforementioned vaginal prolapses. However, since the opening of the vagina has a circular muscle, which is more resistant to dilations than the vaginal cavity, the aforementioned withdrawal of the expanded speculum may cause in patient discomfort and painful sensations. This is because in the course of the withdrawal of the speculum the diameter of its portion at the vaginal opening is stretched by the speculum. Furthermore, the conventional vaginal specula do not have features for measuring the length of vagina and for testing and measuring the severity of the prolapses without completely removing the entire speculum. Normally, the physician disassembles the speculum and inserts only one of the blades for pressing on one wall of the vagina for exposing and observing the opposite wall. In case of prolapses, a separate ruler is used for measuring the length and position of the prolapse or prolapses. The procedure is then repeated for expositing the opposite wall of the vagina cavity. In some cases, the physician uses a separate single metal blade for pressing on the anterior and posterior walls of the vagina cavity. Thus, the examination involves the use of several tools, as well as assembling and disassembling operations. Thus, it is impossible with conventional specula to conduct more concentrated and localized examination of one wall of the vaginal cavity without removing them from the vagina and reinserting other tools one at a time. Such multiple maneuvers are not only very inconvenient and time-consuming but also irritating and uncomfortable to the patient.
Furthermore, the speculum of U.S. Pat. No. 3,716,047 does not allow for observation of the entire periphery of the vaginal cavity without rotating the speculum as a whole, which is undesired and inconvenient.
An attempt to solve a problem associated with possibility of observing the entire periphery of the vaginal cavity is described in U.S. Pat. No. 6,048,308 issued in 2000 to John Strong. The speculum described in this patent is provided with two additional blades insertable into the speculum housing for spreading apart in lateral direction required for observation of the side walls of the vaginal cavity. A disadvantage of this device is that it requires the use of two additional blades. These blades cannot be disconnected from the speculum without removing the latter from the vaginal cavity.
An attempt to solve the problems regarding adjustability of the blades in a longitudinal direction is partially solved in a vaginal speculum described in U.S. Pat. No. 2,579,849 issued in 1951 to Louis Newman. The speculum described in the above patent has blades adjustable in the longitudinal direction by extending their distal ends. The adjustable blades are guided in pivotally interconnected parts and cannot be completely removed from the speculum but can only be shifted forward to increase the blades"" length. Since during the procedure the step formed at the point of protrusion of the adjustable portion from the guiding portion is located inside the vagina, there is a danger of pinching a mucosa during withdrawal of the adjustable blade towards the guide portion. The speculum of U.S. Pat. No. 2,579,849 does not allow for observing side walls of the vaginal cavity without completely removing it from the vagina and replacing with another instrument.
Furthermore, in examining the conditions of the cervix with the use of the aforementioned vaginal specula, it is difficult to diagnose cervical papilomas at the initial stage of their development. This is because such initial papilomas are very small. A papiloma is a growth pattern of epithelial tumors.
U.S. Pat. No. 2,579,849 issued to L. B. Newman in 1951 describes a vaginal speculum with adjustable blades which during the procedure are completely insertable into the vagina and only small distal tips thereof are adjusted inside the vagina. In other words, the adjustable blades of Newman are first inserted into the vagina and then could be adjusted in length by moving forward the distal ends of the blades. The Newman device is first inserted into the vagina only with its constant length and then can be slightly extended forward within the vagina. It can be seen from FIG. 3 of Newman""s patent that the guide portions for the adjustable tips of Newman are completely inserted into the vagina and thus constitute the blades themselves.
The applicants made an attempt to solve the problems of the prior art by developing a vaginal speculum described in U.S. patent application Ser. No. 09/565,613 filed on May 4, 2000, now pending. The vaginal speculum described in the aforementioned patent application consists of two parts pivotally interconnected through a fork-like member. Each part slidingly supports a blade moveable in the longitudinal direction of the speculum so that each blade can be shifted to a required position and fixed in this position for further use. The removeable blades can be withdrawn partially or completely for replacement with blades of other dimensions without withdrawing the entire speculum from the vagina. In a closed state, the distal ends of the blades form a bifocal lens, which can be used for visually detecting changes, associated with an earlier stage of cancer or erosion. Provision of retractable blades makes it possible for a physician to withdraw the blades in an alternating sequence for exposing one of the walls of the vagina cavity by pressing down with the longer blade on the opposite wall. The blades are provided with a scale for measuring the positions and dimensions of the prolapses.
In spite of all the advantages, the vaginal speculum of U.S. patent application Ser. No. 09/565,613 still has some drawback. Though the removeable blades can be shifted to any required position and even completely removed or replaced, the pivotally connected parts that guide the blades are not disconnectable. In some cases, however, a procedure may require that the physician must use only one blade. To accomplish this task with any known vaginal speculum, including the one described in the last-mentioned patent application, the physician has to withdraw the entire speculum from the vagina and replace it with a single-blade instrument. Another disadvantage of the non-disconnectable speculum is that it is inconvenient for cleaning, storage, and packing. Furthermore, the blades can be moved only linearly in a longitudinal direction of the speculum and cannot be moved circumferentially for observation of side walls of the vaginal cavity without replacing, removing or rotating the entire speculum.
It is an object of the present invention to provide a vaginal speculum, in which one of the blade guide parts can be disconnected or the blade can be removed from the speculum without interrupting the procedure. Another object is to provide a vaginal speculum which is convenient for cleaning, storage and packing and which allows observation of the vaginal walls over the entire perimeter of the vaginal cavity without withdrawing, replacing or rotating the entire speculum. Another object is to provide a vaginal speculum having blades moveable in axial as well as in circumferential direction.